When electrons are trapped into the crystal in anion vacancy, the defect is known as :
Schottky defect
Frenkel defect
stoichiometric defect
F-centres
Wave number of a spectral line for a given transition is xcm-1 for He+ then its value for Be+ (iso electronic of H+) for same transition is:
x cm-1
4x cm-1
cm-1
2x cm-1
Dual nature of particle was-given by
Bohr theory
Thomson model
Heisenberg principle
de-Broglie equation
A golf-ball weigh 40.0 gm. If it is moving with a velocity of 20.0 ms-1, it's de-Broglie wavelength is
1.66 x 10-34 nm
8.28 x 10-32 nm
8.28 x 10-25 nm
1.66 x 10-24 nm
Which is the shortest wavelength line in the Lyman series of the hydrogen spectrum? (R= 1.097 x 10-2 nm-1)
94.21 nm
91.16 nm
911.6 nm
933.6 nm
B.
91.16 nm
For Lyman series,
Hence, for to be smallest, n should be greatest (i.e. )
91.16 nm is the shortest wavelength line in the Lyman series of the hydrogen spectrum.
Which of the following order of ionisation energy is correct?
B < Be < N < C
Be > B > C > N
B < Be < C < N
Be < B < C < N